This invention relates to a rotor system of a rotary wing aircraft and, more particularly, to a rotor blade assembly for a rotary wing aircraft.
Conventional rotary wing aircrafts, such as helicopters for example, include a rotor hub configured to rotate about an axis and having multiple rotor blade assemblies mounted thereto. Each rotor blade assembly includes a flexbeam extending outwardly from the rotor hub through the hollow center of a spar or torque tube. The spar is coupled to an outboard end of the flexbeam such that rotation of the rotor hub is transmitted to the spar. The interface between the flexbeam and the spar often requires installation of a plurality of shims and assembly of separate upper and lower spar components. In applications where the interface between the flexbeam and the spar is not near either end of the spar, the installation of shims and other components may be imprecise.
In addition, hard tooling is used to form an inner mold line surface of the torque tube or spar. This type of tooling and the process used to manufacture a spar is complex and intolerant of redesign or development changes to improve the ease of assembling the spar and flexbeam. Generally such changes require large technical and financial investments, as well as a large amount of time.